The objective of this proposal is to develop a Harvard Medical School Research Center in Diagnostic Radiology in which radiologic tools in conjunction with other physiologic, pharmacologic, morphologic, biochemical and biophysical methods may be creatively applied to the solution of biomedical problems. The Center will support a nucleus of investigators in a broad, continuing program oriented particularly toward elucidating the characteristics of the regional circulations in mammals, but by no means limited to such a focus. It will also provide a well-equipped research facility sufficiently versatile and flexible to respond quickly to new and promising directions in research undertaken by faculty and trainees alike. Because there are many combined basic laboratory and clinical research projects already underway, a particular objective of this proposal is clearly feasible; namely, the rapid transfer of advance made in the laboratory to the clinic. Furthermore, the multidisciplinary and multifaceted approaches to problems should provide an objective measure for the interpretation of data obtained with radiographic methods. In the process of developing its research potential, such a Center will also serve as a training resource for investigators and academic radiologists drawn particularly from the Harvard departments and from the medical schools of the New England region.